Carbon nanotube biocompatibility in plants is determined by their surface chemistry

Background Agriculture faces significant global challenges including climate change and an increasing food demand due to a growing population. Addressing these challenges will require the adoption of transformative innovations into biotechnology practice, such as nanotechnology. Recently, nanomaterials have emerged as unmatched tools for their use as biosensors, or as biomolecule delivery vehicles. Despite their increasingly prolific use, plant-nanomaterial interactions remain poorly characterized, drawing into question the breadth of their utility and their broader environmental compatibility. Results Herein, we characterize the response of Arabidopsis thaliana to single walled carbon nanotube (SWNT) exposure with two different surface chemistries commonly used for biosensing and nucleic acid delivery: oligonucleotide adsorbed-pristine SWNTs, and polyethyleneimine-SWNTs loaded with plasmid DNA (PEI-SWNTs), both introduced by leaf infiltration. We observed that pristine SWNTs elicit a mild stress response almost undistinguishable from the infiltration process, indicating that these nanomaterials are well-tolerated by the plant. However, PEI-SWNTs induce a much larger transcriptional reprogramming that involves stress, immunity, and senescence responses. PEI-SWNT-induced transcriptional profile is very similar to that of mutant plants displaying a constitutive immune response or treated with stress-priming agrochemicals. We selected molecular markers from our transcriptomic analysis and identified PEI as the main cause of this adverse reaction. We show that PEI-SWNT response is concentration-dependent and, when persistent over time, leads to cell death. We probed a panel of PEI variant-functionalized SWNTs across two plant species and identified biocompatible SWNT surface functionalizations. Conclusions While SWNTs themselves are well tolerated by plants, SWNTs surface-functionalized with positively charged polymers become toxic and produce cell death. We use molecular markers to identify more biocompatible SWNT formulations. Our results highlight the importance of nanoparticle surface chemistry on their biocompatibility and will facilitate the use of functionalized nanomaterials for agricultural improvement. Graphical Abstract

From Rebellion to Reform: Representations of Regional and Civic Improvement in the Aberdeen Journal, 1747–85

The role of the Aberdeen Journal in facilitating the commercial modernization of Aberdeen and the northeast of Scotland in the four decades after the Battle of Culloden is an understudied aspect of the city's and region's social, economic and cultural history. This article examines the way improvement initiatives from key regional and civic stakeholders like the Board of Trustees for Fisheries, Manufactures and Improvements in Scotland, the Aberdeenshire Society for the Encouragement of Agriculture and Manufactures, the Commissioners of Supply, Aberdeen Town Council, and Marischal College were represented in the newspaper. In particular it highlights how James Chalmers 2 and James Chalmers 3—the Aberdeen Journal's proprietors during its first forty years—developed Scotland's first newspaper north of Edinburgh as an informational hub to integrate the city and region into key currents of Scottish and British capitalist modernization in the second half of the eighteenth century, from linen manufacturing and processing, to land reform and agricultural improvement. The social and economic transformation facilitated by the newspaper led to demands for political reform by those new commercial stakeholders, like John Ewen and Patrick Barron, who had profited from this regional modernization, and the article argues that the Aberdeen burgh reform movement of the early 1780s that utilized the Aberdeen Journal as a principal periodical platform was an essential consequence of this trajectory of regional and civic improvement, and a key test for translating it into a tangible expansion of democratic rights.

9 The Effects of Feeding Cannabidiol Oil on Behavior of Stalled Horses

Using cannabidiol (CBD) in animals has increased since the 2018 Agricultural Improvement Act was passed. Previous work in laboratory animals suggests supplementation with CBD reduced anxiety, compulsive behaviors, and brain activity of limbic and paralimbic areas. Horses exhibit anxiety due to training or housing situations, which is sometimes expressed via stereotypic behaviors including cribbing, aggression, etc. These behaviors can indicate underlying stressors and sometimes causes impairment; therefore, supplementing CBD may reduce undesirable behaviors in horses, consequently improving the health and overall welfare. The study objective was to determine if a single oral dose of CBD would result in adverse effects in horses. Four mature mares and four mature geldings were used in a randomized-control treatment design. Horses typically housed in paddocks, but not novel to stalling were housed in 11’ X 14’ stalls with cameras to record behavior, feed, and water intake. Horses were acclimated to feeding methods and stall environment for one week. Behavior was recorded for 24hr after a dosage of olive oil was administered as a control (CON). Horses were returned to their paddock for one week, then randomly assigned to either a LOW (0.3mg/kg BW; n = 4) or HIGH (0.6 mg/kg BW; n = 4) treatment of CBD oil. After oral dosing, horses were stalled for observation. Stereotypic behaviors such as pawing, cribbing, and aggression were quantified using the Observer XTTM program. Observations were analyzed in R Studio© for analysis of variance (ANOVA). The occurrence of stereotypic behaviors was lower (P = 0.03) in horses given oral CBD. Actions occurred more frequently during feeding sessions, behaviors including aggression and pawing occurred less when horses were given the High dose compared to Control (113 to 26 and 69 to 27) respectively. Based on results, oral administration of the particular cannabidiol product used in this study may mediate negative behaviors in stalled horses.

Carbon nanotube biocompatibility in plants is determined by their surface chemistry

Agriculture faces significant global challenges including climate change and an increasing food demand due to a growing population. Addressing these challenges will require the adoption of transformative innovations into biotechnology practice, such as nanotechnology. Recently, nanomaterials have emerged as unmatched tools for their use as biosensors, or as biomolecule delivery vehicles. Despite their increasingly prolific use, plant-nanomaterial interactions remain poorly characterized, drawing into question the breadth of their utility and their broader environmental compatibility. Herein, we characterize Arabidopsis thaliana transcriptional response to single walled carbon nanotubes (SWNTs) with two different surface chemistries commonly used for biosensing and nucleic acid delivery: oligonucleotide adsorbed-pristine SWNTs, and polyethyleneimine-SWNTs loaded with plasmid DNA (PEI-SWNTs), both introduced by leaf infiltration. We observed that SWNTs elicit a mild stress response almost undistinguishable from the infiltration process, indicating that these nanomaterials are well-tolerated by the plant. However, PEI-SWNTs induce a much larger transcriptional reprogramming that involves stress, immunity, and senescence responses. PEI-SWNT-induced transcriptional profile is very similar to that of mutant plants displaying a constitutive immune response or treated with stress-priming agrochemicals. We selected molecular markers from our transcriptomic analysis and identified PEI as the main cause of this reaction. We show that PEI-SWNT response is concentration-dependent and, when persistent over time, leads to cell death. We probed a panel of PEI variant-functionalized SWNTs across two plant species and identified biocompatible SWNT surface functionalizations. Our results highlight the importance of nanoparticle surface chemistry on their biocompatibility and will facilitate the use of functionalized nanomaterials for agricultural improvement.

Loyalty and Dissent: Improvement and Clearance in Strathspey after 1853

Although Strathspey experienced many of the same trends – agricultural ‘improvement’, enclosure of commons, creation of deer forests, emigration – present elsewhere in Northern Scotland during the nineteenth century, the region was not a flashpoint for unrest. Careful management on behalf of the ruling family, the earls of Seafield, who were the hereditary chiefs of Grant, the local clan; a consistent policy preference to work with existing farming tenants, and a traditional paternalism, all contributed to social stability. The region was not exempt from protest against the impact of the considerable programme of ‘improvement’ pursued from 1853. There were accusations of ‘depopulation’ and ‘clearance’ in Strathspey, but the influence of those who benefitted from the changes, together with the intrinsic and pervasive authority of the Seafield estate, confined discontent to the constitutional channels opening up as the century progressed. Strong expressions of loyalty to the Seafield proprietors were also a feature of the times. Aspects of this narrative of mutual loyalty are examined, and then the spectrum of reaction to improvement and clearance, the growing lobby for land reform, and the experience of depopulation. Although the influence of the Strathspey factor, John Smith, was important in channelling public discourse, a dilution of estate authority as the century progressed is recognised. The article seeks to broaden perceptions of the history of the Highlands by considering a region of the Gaidhealtachd outwith the far North and the North-West.

Genome editing of maize

Developed over thousands of years largely through human intervention, the modern maize genome can now be precisely modified for agricultural improvement and scientific research. This chapter focuses on progress made in recent decades utilizing site-specific nuclease (SSN) technologies in maize genome engineering. Many SSNs, such as meganucleases, zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated proteins (Cas) have been used in maize for both functional analysis and trait improvement. The chapter summarizes the recent innovations related to maize genome editing using SSN technologies, the type of approaches, target genes and traits, and reagent delivery methods. It also discusses the current challenges as well as potential improvements for maize genome engineering protocols.

Insect pollination and sustainable agriculture in Sub-Saharan Africa

We are currently seeing an expansion of pollinator-dependent crops in many parts of the world, but also growing evidence for pollinator population declines and loss of pollinator habitat. Climate change and population growth will place additional demands on crop production, especially in Sub-Saharan Africa (SSA). Despite the wealth of evidence that improved management of insect pollinators can lead to substantial gains in crop yield, agricultural improvement strategies in SSA still emphasize the manipulation of abiotic factors and do not fully exploit the value of pollinators. In this article we review the importance of pollination services in sustainable agriculture, how global perspectives can inform our understanding of the situation in SSA, discuss successful pollination management, highlight where research and development are required, and suggest possible solutions to enhance the contribution of pollination services to sustainable agriculture in the region.

Did the 2018 Farm Bill’s Hemp Provisions Decriminalize Marijuana?

In 2014, Congress removed industrial hemp with a concentration of ≥0.3% tetrahydrocannabinol (THC) dry weight from the definition of marijuana in the federal Controlled Substances Act (CSA). Hemp production was authorized in a limited pilot program until 2018, when Congress passed the Agricultural Improvement Act (Farm Bill) that expanded the program to anyone licensed to produce hemp by the U.S. Department of Agriculture (USDA) or by a USDA-approved State or Indian tribe. Hemp’s greatest value is in two of its 80-plus molecules: cannabidiol (CBD) and THC. These molecules, present in all forms of Cannabis sativa L. (cannabis), including hemp, have medicinal and recreational uses. By removing hemp from the CSA, the Farm Bill altered the legal status of hemp’s extracts, including CBD and THC. In 2018, Epidiolex®, the world’s first and only CBD-based medicine, was approved in the U.S. The drug was placed in Schedule V of the CSA to comply with an international drug treaty requiring control of cannabis and all its extracts. In April 2020, Epidiolex was removed from the CSA schedules. This occurred, according to the Drug Enforcement Administration (DEA), because with a THC content below 0.3%, Epidiolex no longer met the Farm Bill’s criteria as a controlled substance. This review discusses the Farm Bill’s hemp provisions and how they have affected the legal status of hemp derivatives CBD and THC. The review also discusses a loophole in the Farm Bill that decriminalizes the production of marijuana by negligent hemp farmers. In passing, we discuss how lobbying by the hemp/CBD industry influenced passage of the Farm Bill.